Improvement in coiled springs



A. B.. DAVIS.

COILED-SPRING.

Patented Mayl, 1877.

-in the following specification and accompanyface of the bar without additional weight,

as more readily seen in Fig. 3, or the modificylindrical-shaped spring, 0, in which the OF HIS RIGHT TO JOHN B.

IMPROVEMENT IN Specification forming part of Letters Patent No.

QUIRK, OF SAME PLACE.

COILED SPRINGS.

190,291, dated May 1, 1877; application filed February 14, 1877.

To all whom it may concern:

Be it known that I, AUGUSTUS B. DAVIS, of the city and county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in Cylindrical Coiled Springs, which improvement is fully set forth ing drawings, in which- Figure 1 is an end view of a bar of metal from which the blank for the spring will be made. Fig. 2 is a side view of the blank. Fig. 3 is an end view thereof. Fig. 4. is a vertical section of the spring. Figs. 5, 6, 7, and 8 are end views of modifications.

Similar letters of reference indicate corresponding parts in the several figures.

My invention consists of the formation of a spring from a bar which has a centrally coincident tongue and groove, or projection and depression, and coincident shoulders on opposite edges, thus increasing the depth and surwhereby the resilient power of the spring will be increased, and the vertical compass of the spring decreased; and when the spring is compressed or loaded the tongue and grooves on opposite faces of the convolutions will register, or engage and interlock, the tongues being supported on both sides by the grooves, thus preventing lateral displacement of the convolutions or bulge of the spring, and fracture or spreading of the grooved or depressed portion of the spring.

Referring to the drawings, A represents a bar of metal, which is of quadrilateral form in cross section; it is rolled or otherwise wrought into a blank, B, which has a tongue, a, and groove b,-centrally coincident on opposite edges, and which has also coincident shoulders or bearing-faces d on opposite edges,

cations, Figs. 5, 6, 7, and 8.

The blank B will be coiled so as to form a tongue and groove at opposite faces of the convolutions will be in position to register or engage, or the tongue enter the groove,

when the spring is compressed, as seen in Fig. 4.

It will be seen that by the formation of the blank B from the bar A, said blank has a greater depth and surface than the bar; consequently, as the resilient power of a spring is proportionate to the depth and surface of the bar or blank of which it is constructed,the spring constructed of a blank, as herein described, will have its resilient power vastly increased, and it will also possess great strength.

Moreover, when the spring is compressed or loaded, the tongues and grooves of adja cent faces of the convolutions register, or the tongues play in the grooves, interlocking and providing a lateral brace or confine for the convolutions inside and outside, one upon the other, so that the spring will not swell or bulge laterally, whereby the shape, action, strength, and power of the spring are preserved during service, at times when such characteristics are most required, the adjacent shoulders or faces (1 coming in contact, thus restraining the motion of the coils, and preventing fracture or spreading of the grooved or depressed portion of the spring.

It will also be seen that the vertical conipass of the spring is decreased, owing to the fact that the convolutions enter the space of each other, the elevation of the spring being thereby reduced, without, however, interfering with the powerand service of the spring.

The shapeof the tongues and grooves may be angular or curved, or both, and the blank may be constructed of two or more tongues and grooves; but the operation will be the same as that stated, excepting that duplication or multiplication of tongues and grooves will still further increase the resilient power of the spring.

The spring, as constructed, may be inclosed by or inclose other'springs.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The spring having the opposite faces of adjacent convolution, andis supported therein each convolution formed with a centrally-coon both sides and restrained by the bearingincident projection and depression, and coinshoulders, substantially as and for the purcident shoulders or bearing-faces, substanpose set forth.

tially as and for the purpose set forth.

2. A spring having upon its respective DAVIS faces a projection and a depression, and bear- Witnesses: ing-shoulders upon each face, whereby the JOHN A. WIEDERSHEIM,

face of each convolution enters the face of the A. 1?. GRANT. 

